CHAPTER 21 Clean Air: Is It Safe To Breathe?
CHAPTER 21Clean Air: Is It Safe To Breathe?
Air pollution caused by coal burning was a problem during the advent of Industrial revolution.
The air of many cities was blackened with smoke from the industrial and household furnaces and railroad locomotives.
More than 4000 deaths from both respiratory and heart disease were attributed to the foul air.
CRITERIA AIR POLLUTANTS• Clean air act was passed on soon
afterward. Its amendments require monitoring and regulation of six common air pollutants, called criteria air pollutants.
1. PARTICULATE MATTER• Most visible form of air pollution• Particulates in the air have harmful health effects• smallest particles can evade the body's natural defenses,
penetrate deeply into the lungs• populated city were most likely to suffer from respiratory
symptoms
2. SULFUR DIOXIDE• Produced by combustion of sulfur-containing fuel,
especially coal• Most significant impact is as precursor to acid rain• It also tends to stick to fine particulates
3. CARBON MONOXIDE• Highly toxic gas• Most of which is produced in motor vehicle
exhaust• It interferes with the oxygen-carrying capacity of
the blood• Also causes headaches and impairing mental
processes
4. NITROGEN OXIDES• Chemicals responsible for the yellowish-brown
appearance of smog• Main sources are motor vehicle exhaust, off-
road equipment and power plant emissions• It contribute also to acid rain
5. OZONE• Highly reactive variant of oxygen• produced by photochemical reactions• Chronic exposure permanently damages the lungs• Ozone is an important protective component of the upper
atmosphere• But in low altitudes its effects are harmful
6. LEAD• Highly toxic chemical that can damage the
nervous system, blood, kidneys• Main source of lead as an air pollutant is the
use of leaded gasoline
TOXIC & CARCINOGENIC• Toxic chemicals and carcinogenic chemicals are
released into the air by local factories, waste disposal sites, and other sources.
• Emmision standards for such hazards on asbestos, mercury, beryllium, benzene, vinyl chloride, arsenic, radionuclides, coke-oven emissions.
When an area does not meet the air quality standard for one of the criteria pollutants are designated as a nonattainment area and are forced to attain the standard.
STRATEGIES FOR MEETING STANDARDS
• Newest cars have reduced emissions of carbon monoxide and ozone-producing chemicals.
• Ban on leaded gasoline has almost eliminated lead as an air pollutant.
• Requirement of less polluting alternative fuels such as ethanol
STRATEGIES FOR MEETING STANDARDS
• Automakers should develop and market “zero-mandated” vehicles-”electric cars”.
• “Clean Air Act Amendments”, “New Source Review”, “Clear Skies Initiative”, EPCRA.
• Technological improvements in motor vehicles and factories.
INDOOR AIR QUALITY• Most public concern and political action have focused on
outdoor air pollution.• Lack of ventilation may lead to “sick building syndrome”.• “Tobacco smoke”-indoor air pollutant• biological pollutants-bacteria, mold, dust mites, animal dander• “Secondhand smoke”-smoking ban in public places
INDOOR AIR QUALITY• Wood-burning stoves and fireplaces emit particulate matter and
gases.• Pesticides, dry-cleaning solvents, paints and thinners, air fresheners.• airborne microbes can pose health hazards• Legionnaire's disease due to aircon• Hantavirus from rodent urine or feces
GLOBAL EFFECTS OF AIR POLLUTION
• Acid rain-It damages forests, corrosion• Aidic rivers and lakes• Depletion of the ozone layer-“CFCs”• Greenhouse effect• “Global warming”
CONCLUSION• Air pollution is a threat to health• Leads to deaths from respiratory disease
and heart disease• “Global scale”implementations on
interventions to be effective• There are 6 criteria air pollutants• Strategies for meeting standards include
technological improvements
CONCLUSION• Common indoor pollutants such as
smoking and also biological air pollutants.• Air pollution create acid rain, depletion of
ozone layer, greenhouse effect that lead to global warming.